Field of the Invention
Embodiments of the present invention generally relate to a method and apparatus for converting DC input power to AC output power with reactive power control.
Description of the Related Art
A power factor (PF) of an AC electrical power system is defined as the ratio of real power flowing to a load versus the apparent (or reactive) power of the circuit. Distributed generators (e.g., photovoltaic (PV) panels, wind turbines, and the like) rely on power converters such as flyback converters to convert DC power to AC power. Such DC-AC inverters in PV applications have been traditionally required by legislation to only supply real power with no reactive power, hence for any converted power, the power factor is typically required to be at or near unity.
With increasing use of renewable energy generation there is a need to allow power network operators to exercise the control over the new sources renewable energy just as well as conventional sources of energy generation. Accordingly, DC-AC inverters, for example, for PV applications must be able to provide what is known as “reactive support”. The inverters must be capable to deliver not only real power, but also a predetermined amount of reactive power. The amount of reactive power cumulatively supports the power on the AC grid and allows DC power from distributed generators to more effectively contribute power to the AC grid.
Therefore, a need exists in the art for a method and apparatus for providing power conversion using converters with reactive power control.